Magnetically-controlled mercury-vapor apparatus and the like.



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MAGNETICALLY CONTROLL CURY VAPOR APPARATUS AND THE LIKE. APPL FlLEDSEPTaIZ.) |914.-

51,212,774, 'Pat d Jan.16,1917.

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, i I "TTOREY'S Y n J. JONAS.`

MAGNETICALLY CONTROLLED MERCURY VAPOR APPARATUS AND THE LIKE.

` APPLICATION FILED'SEPTJZ. |9114.

k3 2 SHEETS-SHEET 2- I b l l WITNESSES l INVENTR 69E/doc 74% 4M A' BY v'fu/16am fana/esj WMJ-W- wlwmn'Us JULIUS JONAS,-OF BADEN, SWITZERLAND, ASSIGNOR T0 AKTIENGESELLSCHAFT Y BOYERI & CIE., OF BADEN, SWITZERLAND.

En STATES PATENT oF-Fro MAGNETICALLYPCONTROLLED MERCURY-VAPOR APPARATUS AND THE LIKE.

Specification of Letters Patent.

Patented J an.. 16, 1917.

Application tiled September 12, 1914. Serial No. 861,467.

To all whom it may concern.'

Be it known that I, JULIUS JONAS, a sub-v ject of the German Emperor, of Brugger-l obstacle, for instance a sharp edge or a wall,

then there first takes place a magnetic compression of the stream lines toward the obstacle to the deflection, and the consequent contraction of the cross section for the passage of the current produces an increased resistance in the circuit of the electric arc. If the magnet is gradually strengthened, the resistance will rise gradually to a value at which the electric arc will break and the resistance value will finally become infinite..

The broken electric arc does not re-form so long as the magnetic field retains the value necessary for interrupting the current; this can be explained as follows It is assumed that in addition to the electrodes proper there are provided also igniting electrodes as is well known see for instance U. S. Patent No. 877 ,026, through which the current flows permanently and which are not under the influence of the magnetic field. These igniting electrodes energize the main electrodes in such a manner that an electric arc is at once formed between them, as soon as the magnetic field falls below the aforesaid limit value.

The electric arc is produced by the fact that at first ions are thrown off by the cathode and thus reach the anode and constitute a bridge over which the electric arc is formed. The ions are, however, likewise deflected in their course by the magnetic field and are unable to constitute a bridge between the main electrodes so long as the magnetic field has not dropped below the limit value. Consequently vby maintaining a corresponding magnet field, the electric y arc current can be permanentlyI interrupted,

but; only when there is an obstacle to the shifting vof4v the stream lines. Otherwise only 'a defiection of the electric arc takes place wlthout any substantial increase of res1stance.

. In the accompanying diagrammatic drawmgs: Flgure 1 isan elevation, and Fig. 2 a part sectional plan of a magnetically controlled mercury vapor cell; Figs. 3 to 9 aref. part sectional plans of various modifications according to the present invention in which: Flg. 3 shows a form with a comparatively sharp edge for breaking the arc; Fig. 4 shows an arrangement With a tube of rectangular section for containing the arc yplaced. between the poles of a magnet but eccentric thereto, that is to say the center llne of the poles is not coincident with the center llne of the tube. Fig. 5 illustrates a modification with a tube of triangular'sec-v tion; Fig. 6 indicates a further modification in which the magnet is excited both by direct and by alternating current; Fig. 7 illustrates amagnet with gaps for two vapor cells, and Fig. 8 shows a modification arranged forthree-phase current; Fig. 9 illustrates a form in which'a single-phase arc is sub-divided into three parts controlled by magnets excited both by direct and by alternating current.

In the well known arrangement shown in Figs. 1 and 2, the wall q of the vessel composed of glass constitutes the obstacle tothe shifting of the electric arc Z, and the electric arc is as it were crushed against this wall by the field of the magnet m. On energizing the magnet with alternating current,

there occurs during ever half period a field maximumand if the excltation is sufficiently powerful the electric arc which is generated for instance with direct current, can be extinguished twice during one period of the alternating current. The electric arc direct current is thus converted into a pulsating direct current which can be decomposed into a direct current and an alternating current of double the frequency of the e'xclting current. `This alternating current of double frequency may be utilized for producing high frequency by using it for instance again as an energizing alternating current and thus obtaining alternating current of quad- BROWN,l

ruple frequency, &c. In many cases the doubling of the frequency is notdesired and it is then undoubtedly a drawback of the well known. arrangement. The object of the resentinvention 1s to provide a magnetica ly controlled mercury ergized by means' of alternating current is provided with pole pieces p1 p2 whose mutuallyfacing` surfaces have the shape of two horns'. The density of the lines offorce between these faces therefore in different planes is dierent and is greatest at the' point where the pole surfaces are nearest together. At this point there is situated the sharp edge s which is made of conducting or non-conducting and preferably non-magnetic material, serving as an obstacle to the shifting of the electric'arc Z which when the vmagnets are not energized, is able to pass through the plane of the figure, say at the point indicated bya dotted circle.

' If the magnet be energized by means of alternating current, then the cross section ofthe electric arc Z will move either toward s or away from s. In the latter case no appreciable increase in resistance jdue'to the influence of the magnet will take place, especially as the electric arc' moves out of the scope of the field. In the case where Z moves toward s, it will come into\a field of increasing density and will bepresse'd against the sharp .edge s and finally broken. This breaking .thus occurs only during one' direction of the exciting current, that is to say, only during one half period in the case of alternating current,whi1e the electric arc renains existent during the other half per1o In Fig. 4 instead of the sharp edge s of Fig. 3 a wall or a guide tube 1' for the electric arc is employed, which tube is located eccentrically for instance in the case of 'parmiddle line e e of the poles. In the case of energization in the one direction the electric arc is pressed toward the side w and in the other direction the tube is so situated that the arc is shifted toward y. When the arc is magnetically impelled toward side allel pole surfaces as shown opposite the' Lamme.

section for the purpose of moving the electric arc into a field of increasing density when moving toward w.

The object in view may be attained in another way by mixed excitation of the controlling magnet. In the arrangement shown in Fig. 6, a direct'current field is superposed on the alternating current fieldf If the value of the direct current field be equal to the maximum valueof ythe alternating field, then the exciting ampere turns will be l, added together during the one half period,

and' will be subtracted during the other half period. If the direct current field be made such that it is just sufcient for interrupting the electriczarc led between walls or sharp edges, then the electric-arc will be broken during one half period and will be re-formed during the other half period.

In the arrangement shown in Fig. 6, a choking coil d is provided for renderlng inoperative the mutual induction of the alternatingcurrent winding fw upon the direct kcurrent winding .g of the controlling magnet.'

When a number of electric arcs are controlled by magnets whose alternating currents are taken from thedifferent phases of a polyphase net. or whose phase difference is the same in passing through the cycle, then the E. M. F.s, induced in the direct current windings will cancel one another, if the direct current windings of all the magnets are connected in series. It is not then necessary to insert an inductive resistance.

Fig. 7 illustrates the case where two electric arcs Z1 Z2 are controlled with a phase shifted 180. The two magnets are combined to form a double magnet fm. which although having the two series connected direct current wlndings g1 and g2, is yet energized by a common alternating current winding w. The alternating field of either half of the magnet is then shifted 180 relatively to the other half ofthe magnet, and is added to the direct current field in the one half of the magnet, while it is subtracted in the other half. The direct current field Passes through i1 i2 k3 :va p2 p2 p1 la, the alternating field passes through k2, and

`is then divided into two parts ofwhich the one part passes through p2 p1l s:1 jl, and the other passes through p2 p3 k3 jz. The E. M. F.s induced in the two windings g1 and g2 cancel each other completely.

In the form shown in Fig. 8 which applies to a three-phase system the three arcs l, Z2 Z3 are inclosed in tubes r1 rz r3 controlled by themagnet, m, with the three cores lc, k2 1.23 carrying alternating current windings 'w1 w2 andfw3 on which are mounted the direct current windings g, g2 g3 g4 g5 and ge. The direct current windin are energized from the battery b and the altervnaamw-1. y

natin current windings from the generator a( T e arcs and the magnets are inclosed in the common vacuum vessel g. The direct current flux generated by the coils gl---ge continues directly by way of the pole pieces p and the arcs Z, in the order of suc- Cession/271 la p2, p2 Z1 ps pa Z2 p1 p19 While the flux of the three coils lw1 w2 *ws changes according to the momentary value of the three phase currents. For instance,l if the coil w1 has a momentary maximum positive terminal potential and if at the same time the other two coils lw2 and w3 have half the negative terminal potential, then at that moment the maximum flux generated by them is divided from the core f:1 on the one hand through p1 Z3 p2 k2 and the yoke m, and von the other hand through p1 Z2 p3 k', and m back to k1. VNext k2 has the strongest field, then k3 and so on. There is in fact a three-phase field. As will be seen, at that moment in the path p1 Z3 11, the alternating field is added tothe direct current field, whereas in the path p1 Z2 p3 it is subtracted from the direct current field, while in the path p2 Z1 p3 it is m'l. The path of the direct current field is marked I, and the path of the momentary value (given by way of example) of the alternating field (three-phase field) is marked II.

The direction of the direct current ampere turns must be so chosen that the shifting of the electric arc in the case of the adding together of the direct current field and alternating current field sh'all take place into the field of increasing density (in Fig. 8 therefore toward-the axis of the cylindrical vessel). It is an advantage to cause the electric arc to shift toward the interior of the vessel because this allows of a convenient way of cooling and carrying off the heat (e. g. by parts c referred to below) for it is required to carry off in a suitable manner the losses of energy which occur in the electric arc by reason of the increase of resistance therein.

The windings must be so arranged that the heat generated in the electric arc shall not pass over to them. For this purpose the windings are arranged as far as possible at the periphery of the vessel where they can be effectively cooled from the outside.

In Fig. 9 each electric arc is divided into a number of partial arcs, and an equal number of simultaneously energized magnets made to act upon these partial arcs, the magnets being arranged in such a manner that each partial are is situated between the north pole of one magnet and the south pole of the other magnet. The form illustrated in Fig. 9 comprises a mono-phase electric arc which is divided into three partial arcs. These partial arcs are connected up in parallel and are intended to be all extinguished simultaneously by the controlling magnets,

in which the three parts are contained in al common vessel. The flux has its course along the line'III, that is to say the direct current 'field has always the direction of the arrows I, while the alternating current field has alternately the same or the opposite direction, as indicated by the arrows II and IV.

As with Fig. 8 a battery b is provided for excitingy the direct current windings, and a generator a for the alternating current field. In addition an inductance d is illustrated as in Fig. 6. It has been assumed that the coils' are connectedv in series, but they might have been connected in parallel. In this arrangement the windings do not come in contact at all with the guiding tubes of the electric arcs. If the electric arcs be shifted toward the interior of the vessel for the purpose of being broken, then the resulting losses will also occur in the interior of the vessel, where they are carried off to t-he outside by a system of cooling pipes which is provided with cooling ribs c -cl and is traversed by cooling fluid. This system of cooling pipes is preferably made of nonmagnetie material.

The cooling fluid may be admitted through theI inner pipe c1 of the coolingpipe system and be discharged through the outer pipe c so that the entire system requires only one aperture for admittance into the vacuum vessel. f

In Fig. 9 both as regards the direct cur rent excitation, as well as regards the alternating current excitation there is always a south pole arranged opposite a north pole so that every utilizable line of force traverses all three electric arcs.

It is an advantage to make the windings of enameled wire, because such wire is free.

from the porosity which would hinder the formation and maintenance of a good vacuum, and also because enameled wire is resistant to heat and can be cooled more easily than wire which is insulated in the ordinary wav. Enamel has the further property (which is especially valuable in the case of mercury vapor cells) of preventing the amalgamation of the wire and of itself being unattacked by mercury.

The particular form of pole pieces and obstacles shown in Figs. 3 to 5 may also be employed in the case of a magnet with I mixed energization.

Instead of the constant direct current a pulsating direct current may be employed.

In the arrangement shown in Fig. '7 the common winding w may be excited by direct current, and the other windings g1 and g2 by alternating current.

The arrangement shown in Fig. 7 may also for example as shown in Fig. 8 be applied to three electric arcs controlled with a phase' difference of 120, as well as generally to polyphase arrangements of vany desired number of phases.

Having now described my invention, what I claim as new and desire to secure by i Letters Patent is 4l. In. combination a mercury vapor apparatus or the like, a controlling electromagnet disposed in proximity thereto, means for supplying current of varying direction to said magnet and means for interrupting the electric arc of the vapor apparatus, only once during one period of the' exciting current.

2. In comblnatlon a mercury Vapor lamp or the like including a guiding tube for the -arc an electromagnet with two windings an with tapering pole faces, said magnet being disposed in proximity to said tube but eccentric thereto, means for supplying an alternating current to one winding of the electromagnet, and means for supplying a direct current to the other Winding of the electromagnet, the currents being such that once for every period of this current the arc is driven into a field of such 'densitythat it is broken.

4. In combination a mercury vapor lamp or the like including a guiding tube for the arc, an electromagnet disposed in proximity to said'tube but eccentric thereto, two windings on said magnet, means for supplying an alternating current to one winding and means for supplying a direct current to the other winding, the currents being such that once' for every period of this current the arc is driven into a field of such density that it is broken.

In testimony whereof, I have aHiXed my g 

